SOI Operational Amplifier Applications in 300°C Operating Environment

2017 ◽  
Vol 2017 (HiTEN) ◽  
pp. 000109-000112
Author(s):  
Cheng-Po Chen ◽  
Lucian Stoica ◽  
Emad Andarawis ◽  
Russell Simpson

Abstract A custom designed SOI operational amplifier (opamp) is used in two application circuits and characterized up to 300°C: 1. An instrumentation amplifier (in-amp) with a differential voltage gain of 100, and 2. A transimpedance amplifier (TIA) with a gain of 1.2 giga Ohm, used to sense picoamp level signals. The opamp operates with a 5-volt supply, and has rail-to-rail inputs and outputs. The open loop gain of the opamp is about 100 dB at room temperature and stays above 60 dB at 300°C. The in-amp uses the classic three operational amplifier (opamp) architecture with off-chip feedback resistors. The closed loop gain of the in-amp remains stable at 100, up to 250°C, and drops to 95 at 300°C. Temperature dwell test shows the in-amp maintaining stable functionality at 300°C for at least 1000 hours. The TIA also incorporates a silicon carbide diode to achieve gain compression by lowering the feedback gain when the input signal is higher, thus allowing a higher dynamic range input before the circuit output saturates.

2010 ◽  
Vol 2010 (HITEC) ◽  
pp. 000305-000309 ◽  
Author(s):  
Vinayak Tilak ◽  
Cheng-Po Chen ◽  
Peter Losee ◽  
Emad Andarawis ◽  
Zachary Stum

Silicon carbide based ICs have the potential to operate at temperatures exceeding that of conventional semiconductors such as silicon. Silicon carbide (SiC) based MOSFETs and ICs were fabricated and measured at room temperature and 300°C. A common source amplifier was fabricated and tested at room temperature and high temperature. The gain at room temperature and high temperature was 7.6 and 6.8 respectively. A SiC MOSFET based operational amplifier was also fabricated and tested at room temperature and 300°C. The small signal open loop gain at 1kHz was 60 dB at room temperature and 57 dB at 300°C. Long term stability testing at 300°C of the MOSFET and common source amplifiers showed very little drift.


2002 ◽  
Vol 282 (3) ◽  
pp. H1149-H1156 ◽  
Author(s):  
Toru Kawada ◽  
Can Zheng ◽  
Yusuke Yanagiya ◽  
Kazunori Uemura ◽  
Tadayoshi Miyamoto ◽  
...  

A transfer function from baroreceptor pressure input to sympathetic nerve activity (SNA) shows derivative characteristics in the frequency range below 0.8 Hz in rabbits. These derivative characteristics contribute to a quick and stable arterial pressure (AP) regulation. However, if the derivative characteristics hold up to heart rate frequency, the pulsatile pressure input will yield a markedly augmented SNA signal. Such a signal would saturate the baroreflex signal transduction, thereby disabling the baroreflex regulation of AP. We hypothesized that the transfer gain at heart rate frequency would be much smaller than that predicted from extrapolating the derivative characteristics. In anesthetized rabbits ( n = 6), we estimated the neural arc transfer function in the frequency range up to 10 Hz. The transfer gain was lost at a rate of −20 dB/decade when the input frequency exceeded 0.8 Hz. A numerical simulation indicated that the high-cut characteristics above 0.8 Hz were effective to attenuate the pulsatile signal and preserve the open-loop gain when the baroreflex dynamic range was finite.


2011 ◽  
Vol 679-680 ◽  
pp. 730-733 ◽  
Author(s):  
Zachary Stum ◽  
Vinayak Tilak ◽  
Peter A. Losee ◽  
Emad A. Andarawis ◽  
Cheng Po Chen

MOSFET-based integrated circuits were fabricated on silicon carbide (SiC) substrates. SiC devices can operate at much higher temperatures than current semiconductor devices. Simple circuit components including operational amplifiers and common source amplifiers were fabricated and tested at room temperature and at 300°C. The common source amplifier displayed gain of 7.6 at room temperature and 6.8 at 300°C. The operational amplifier was tested for small signal open loop gain at 1kHz, measuring 60 dB at room temperature and 57 dB at 300°C. Stability testing was also performed at 300°C, showing very little drift at over 100 hours for the individual MOSFETs and the common source amplifier.


2016 ◽  
Vol 72 (2) ◽  
pp. 236-242 ◽  
Author(s):  
E. van Genderen ◽  
M. T. B. Clabbers ◽  
P. P. Das ◽  
A. Stewart ◽  
I. Nederlof ◽  
...  

Until recently, structure determination by transmission electron microscopy of beam-sensitive three-dimensional nanocrystals required electron diffraction tomography data collection at liquid-nitrogen temperature, in order to reduce radiation damage. Here it is shown that the novel Timepix detector combines a high dynamic range with a very high signal-to-noise ratio and single-electron sensitivity, enablingab initiophasing of beam-sensitive organic compounds. Low-dose electron diffraction data (∼0.013 e− Å−2 s−1) were collected at room temperature with the rotation method. It was ascertained that the data were of sufficient quality for structure solution using direct methods using software developed for X-ray crystallography (XDS,SHELX) and for electron crystallography (ADT3D/PETS,SIR2014).


2009 ◽  
Vol 19 (1) ◽  
pp. 7-12
Author(s):  
Nikola Jorgovanovic ◽  
Dubravka Bojanic ◽  
Vojin Ilic ◽  
Darko Stanisic

We present the design, simulation and test results of a new AC amplifier for electrophysiological measurements based on a three op-amp instrumentation amplifier (IA). The design target was to increase the common mode rejection ratio (CMRR), thereby improving the quality of the recorded physiological signals in a noisy environment. The new amplifier actively suppresses the DC component of the differential signal and actively reduces the common mode signal in the first stage of the IA. These functions increase the dynamic range of the amplifier's first stage of the differential signal. The next step was the realization of the amplifier in a single chip technology. The design and tests of the new AC amplifier with a differential gain of 79.2 dB, a CMRR of 130 dB at 50 Hz, a high-pass cutoff frequency at 0.01 Hz and common mode reduction in the first stage of the 49.8 dB are presented in this paper.


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